Update doesn't work on Elasticsearch 7.11

[To-om]

After updating to Elasticsearch 7.11, document without relation cannot be updated. The error message is:

ElasticError(mapper_parsing_exception,failed to parse,None,None,None,
List(ElasticError(mapper_parsing_exception,failed to parse,None,None,None,null,None,None,None,List())),
Some(CausedBy(illegal_argument_exception,unknown join name [sequence] for field [relations],Map())),
None,None,List())

Before ES7.11, join field can be used to store document type, even if there is no relationship. From ES 7.11, a dedicated field must be used to store document type.